Hot melt pressure sensitive adhesives

Abstract

A coated abrasive disc is described in which the non-abrasive bearing surface of the disc is provided with a pressure sensitive adhesive which comprises an aliphatic polymer, such as a propylene/1-butene/ethylene terpolymer; an aliphatic oil, such as a low molecular weight polybutene; and a tackifying aliphatic resin.

What is claimed is: 
     
       1. An abrasive sheet material comprising a backing material having an abrasive layer secured to one face and a pressure sensitive adhesive layer on the opposed face wherein the pressure sensitive layer comprises: a) from about 10 to about 50% by weight of an aliphatic power selected from the group consisting essentially of ethylene/propylene rubbers, ethylene/butylene rubbers, ethylene/propylene/diene rubbers, ethylene/1-butene/propylene polymers and butyl rubbers;   b) from about 10 to about 50% by weight of an aliphatic oil selected from the group consisting essentially of low molecular weight polybutenes, naphthenic-paraffinic oils and naphthenic-paraffinic oils with a slight aromatic content; and   c) from about 10 to about 70% by weight of an aliphatic resin selected from the group consisting essentially of polyterpenes, mixed olefin/diolefin polymers and olefin hydrocarbon polymers, dicyclopentadiene, hydrogenated C 9  resins, hydrogenated aromatic resins and debutanized aromatic concentrates-B.   
     
     
       2. An abrasive sheet according to claim 1 in which the formulation also comprises an antioxidant. 
     
     
       3. An abrasive sheet according to claim 1 which additionally comprises an additive that retards the migration of low molecular weight components within the formulation selected from polyethylene waxes, ethylene/butylene polymers with polystyrene end caps, and mixtures of such additives. 
     
     
       4. An abrasive sheet material comprising a backing material having an abrasive layer secured to one face and a pressure sensitive adhesive layer on the opposed face wherein the pressure sensitive layer comprises: a. from about 15 to about 30% by weight of a propylene/1-butene/ethylene terpolymer;   b. from about 10 to about 20% by weight of a low molecular weight polybutene;   c. from about 10 to about 20% by weight of polyisobutylene rubber; and   d. a low molecular weight aliphatic hydrocarbon tackifying agent in an amount sufficient to give the formulation the desired level of pressure sensitivity.   
     
     
       5. An abrasive sheet according to claim 4 in which the pressure sensitive formulation additionally comprises from about 5 to about 10% by weight of a thermoplastic rubber comprising an ethylene/butylene copolymer with polystyrene end caps. 
     
     
       6. An abrasive sheet according to claim 4 in which the pressure sensitive formulation additionally comprises from about 5 to about 10% by weight of a polyethylene wax. 
     
     
       7. An abrasive sheet according to claim 4 in which the pressure sensitive formulation additionally comprises an antioxidant. 
     
     
       8. An abrasive sheet according to claim 4 in the form of a disc. 
     
     
       9. An abrasive sheet according to claim 4 in which the backing material is a paper. 
     
     
       10. An abrasive sheet in the form of a disc wherein the disc comprises a paper backing material with an abrasive layer adhered to one face and a pressure sensitive adhesive layer on the other surface in which the pressure sensitive adhesive comprises: a. from about 15 to about 20% by weight of a propylene/1-butene/ethylene terpolymer;   b. from about 15 to about 20% by weight of a low molecular weight polybutene;   c. from about 10 to about 15% by weight of a polyisobutylene rubber;   d. from about 30 to about 45% by weight of a low molecular weight aliphatic hydrocarbon tackifying agent;   e. from about 5 to about 10% by weight of a polyethylene wax; and   f. from about 5 to about 10% by weight of a thermoplastic rubber comprising an ethylene/butylene coplymer with polystyrene end caps and wherein the end caps represent from about 5 to about 15% of the weight of the thermoplastic rubber.   
     
     
       11. An abrasive disc according to claim 10 in which the pressure sensitive adhesive further comprises up to 0.5% by weight of an antioxidant.